Create aggregates.sql

Author: erjan

pgexercises/aggregates.sql

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+
+
+
+select count(*) from cd.facilities
+
+select count(*) from cd.facilities where guestcost >=10
+
+select recommendedby, count(recommendedby) as count 
+from cd.members 
+where recommendedby is not null
+group by recommendedby
+order by recommendedby
+
+select f.facid , sum(slots) as total_slots from cd.bookings b inner join cd.facilities f on f.facid = b.facid
+group by  f.facid
+order by f.facid
+
+
+select f.facid , sum(slots) as total_slots 
+from cd.bookings b inner join cd.facilities f on f.facid = b.facid
+where starttime::date >= '2012-09-01' and starttime::date < '2012-10-01'
+group by  f.facid
+order by total_slots
+
+select f.facid , extract(month from date(starttime)) as month, sum(slots) as total_slots 
+from cd.bookings b inner join cd.facilities f on f.facid = b.facid
+where starttime::date >= '2012-01-01' and starttime::date < '2013-01-01'
+group by  f.facid, extract(month from date(starttime))
+order by f.facid, month
+
+
+
+select  count(distinct cd.members.memid)  as count
+from cd.members inner join cd.bookings 
+on cd.members.memid = cd.bookings.memid
+-- group by cd.members.memid
+having count(cd.bookings.facid) > 1
+
+
+select facid, sum(slots) as total_slots from cd.bookings
+group by facid
+having sum(slots)> 1000
+order by facid
+
+
+select f.name , 
+
+sum( slots * case when memid = 0 then f.guestcost else f.membercost end) as revenue
+from cd.bookings b inner join cd.facilities f on b.facid = f.facid
+group by f.name
+order by revenue
+
+
+
+select f.name,
+sum( slots * case when memid = 0 then f.guestcost else f.membercost end) as revenue
+from cd.bookings b inner join cd.facilities f on b.facid = f.facid
+group by f.name
+having sum( slots * case when memid = 0 then f.guestcost else f.membercost end) < 1000
+order by revenue
+
+
+select facid, sum(slots) as total_slots from cd.bookings
+group by facid
+order by total_slots desc limit 1 
+
+--alternative messy limitless version:
+select facid, sum(slots) as total_slots from cd.bookings
+group by facid
+having sum(slots) = (select max(k) from (select facid, 
+										sum(slots) as k from cd.bookings group by facid)o)
+
+
+--alternative messy limitless version 2:
+
+select facid, max(totalslots) from (
+	select facid, sum(slots) as totalslots    
+		from cd.bookings    
+		group by facid
+	) as sub group by facid
+	
+	
+	
+	
+select facid, 
+extract(month from date(starttime)) as month, 
+sum(slots) as slots from cd.bookings where extract(year from date(starttime)) = '2012'
+
+group by rollup(facid, extract(month from date(starttime)))
+order by facid, month
+
+
+select f.facid, f.name ,
+
+trim(to_char(sum(b.slots)/2.0,'9999999999999999D99'))   as total_hours
+
+from cd.bookings b inner join cd.facilities f on b.facid=f.facid
+group by f.facid , f.name
+order by f.facid
+	
+	
+-- логика - выбрать первый букинг - это все даты больше 2012 сент и первый из них - это минимальный!!!
+select  surname, firstname, cd.members.memid, min(starttime) as starttime
+from cd.members 
+inner join cd.bookings 
+on cd.members.memid = cd.bookings.memid 
+where starttime::date >= '2012-09-01'
+group by surname, firstname, cd.members.memid
+order by cd.members.memid
+	
+
+	
+select (select count(*) as k from cd.members) ,
+ firstname,surname 
+from cd.members m  
+order by m.joindate
+
+
+select row_number() over( order by joindate) ,
+firstname,surname
+from cd.members
+
+
+select facid, total from (
+
+select facid, sum(slots) as total, 
+rank() over (order by sum(slots) desc) as rank 
+from cd.bookings group by facid) as ranked
+where rank =1 
+
+
+-- my solution
+select rank2.name, 
+rank() over (order by rank2.revenue desc) as ranky from 
+(select f.name, 
+sum( slots * case when memid = 0 
+then f.guestcost else f.membercost end) as revenue
+from cd.bookings b inner join cd.facilities f on b.facid = f.facid
+group by f.name) rank2
+ order by ranky limit 3
+ 
+ 
+select name, rank from (
+	select facs.name as name, rank() over (order by sum(case
+				when memid = 0 then slots * facs.guestcost
+				else slots * membercost
+			end) desc) as rank
+		from cd.bookings bks
+		inner join cd.facilities facs
+			on bks.facid = facs.facid
+		group by facs.name
+	) as subq
+	where rank <= 3
+order by rank;    
+
+
+
+
+
+select 
+firstname,surname,hours, 
+rank() over( order by hours desc) as rank
+
+		from (select m.firstname, m.surname, ((sum(b.slots)+10)/20)*10 as hours
+		
+		from
+		cd.bookings b
+		inner join cd.facilities f on b.facid = f.facid
+		inner join cd.members m on m.memid = b.memid
+		group by m.firstname, m.surname)k
+		order by rank, surname, firstname
+		 
+ 
+ 
+ select name, case when class = 1 then 'high' when class = 2 then 'average' else 'low' end as revenue from 
+(select f.name as name, 
+
+ntile(3) over (order by 
+									  
+									  sum(
+										case when memid = 0 then slots * f.guestcost
+										else slots * membercost end) desc ) as class
+										from cd.bookings b inner join cd.facilities f on f.facid = b.facid
+										group by f.name) as subq
+										order by class,name
+										
+										
+										
+										select 	facs.name as name,
+	facs.initialoutlay/((sum(case
+			when memid = 0 then slots * facs.guestcost
+			else slots * membercost
+		end)/3) - facs.monthlymaintenance) as months
+	from cd.bookings bks
+	inner join cd.facilities facs
+		on bks.facid = facs.facid
+	group by facs.facid
+order by name;        
+
+
+select 	dategen.date,
+	(
+		-- correlated subquery that, for each day fed into it,
+		-- finds the average revenue for the last 15 days
+		select sum(case
+			when memid = 0 then slots * facs.guestcost
+			else slots * membercost
+		end) as rev
+
+		from cd.bookings bks
+		inner join cd.facilities facs
+			on bks.facid = facs.facid
+		where bks.starttime > dategen.date - interval '14 days'
+			and bks.starttime < dategen.date + interval '1 day'
+	)/15 as revenue
+	from
+	(
+		-- generates a list of days in august
+		select 	cast(generate_series(timestamp '2012-08-01',
+			'2012-08-31','1 day') as date) as date
+	)  as dategen
+order by dategen.date; 
+
+